From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 149BE35C69A; Tue, 21 Jul 2026 21:35:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784669726; cv=none; b=j5DHaRDXBvUcI28QOlaXwTtXgA64uzO1Q/6eqbAG9EVJrSykag/1Omk5nc4ccUUu4/g0j6+5jV0LyaYu8geNOuvE48bPji47lB4LGfGuPfZWmcHWf/v6T8vo4zYPE/dlp4FQHEiQkxRNRy9pTozMO4o6SL19FHIXt5q8oG5qy6c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784669726; c=relaxed/simple; bh=AfBT+tjf5n88gF+QS08QxfcZv+hn165a493+oxe6yTQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qNELTLg60QtsqVaTXJG5bCE8a6fCMByhguR2wSBF6GGXVyQZCGSj7kQemc5hJl0IW9s6HB1u3TI/KrOqLVpxscHjliYbRqY4Ft7ZJxvduFxQVv7UV0y8Ye+41U/qScQDeeIRW7ovvrT3Tk1PrC1tXt9Yj2aIB56GP7AMnvOAPLg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=KArwXtyn; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="KArwXtyn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E7931F000E9; Tue, 21 Jul 2026 21:35:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784669724; bh=GcvdgEkcNlcJWyPRToQlaNlKFznh6WQHHqnTD7vqr0c=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=KArwXtynBjki6DO2N1QmQPzsG6pNXDhVCv/MdaZK1ZO0nVhi4EmqiJ8x6aUCynKE+ Ayft4QzytLjdaLrY/5k2Vxuu20BzcPx4p7ydnKy6C/J8fBqZMvkcz+5YhPx0sQtwSy iFQ5Z6TJ7XbEV/o2NwRc+WCWyS3jBZZEOVxOIhwY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Michael S. Tsirkin" , Longjun Tang , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.1 0664/1067] virtio_net: disable cb when NAPI is busy-polled Date: Tue, 21 Jul 2026 17:21:05 +0200 Message-ID: <20260721152439.450544771@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152424.521567757@linuxfoundation.org> References: <20260721152424.521567757@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Longjun Tang [ Upstream commit 1eb8fc67ca41db71c90866ff76c990d85247daef ] When busy-poll is active, napi_schedule_prep() returns false in virtqueue_napi_schedule(), so virtqueue_disable_cb() is skipped. The device may keep firing irqs until reaches virtqueue_napi_complete(). Under load (received == budget), it will lead to a large number of spurious interrupts. Fix it by disabling the callback at the virtnet_poll() entry. This keeps the callback off while we poll and it is re-enabled by virtqueue_napi_complete() when going idle. Fixes: ceef438d613f ("virtio_net: remove custom busy_poll") Acked-by: Michael S. Tsirkin Signed-off-by: Longjun Tang Link: https://patch.msgid.link/20260629024230.37325-1-lange_tang@163.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/virtio_net.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 9bbb26efb82573..23362ef9cb8c35 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1709,6 +1709,9 @@ static int virtnet_poll(struct napi_struct *napi, int budget) unsigned int received; unsigned int xdp_xmit = 0; + if (budget) + virtqueue_disable_cb(rq->vq); + virtnet_poll_cleantx(rq, budget); received = virtnet_receive(rq, budget, &xdp_xmit); -- 2.53.0